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Lets us read on blog which is basically based on energy conservation measures in building, we will consider one building.

Whose descriptions are as following and after that we will consider energy conservation measure that might be implemented in order to reduce the energy cost.

We will consider every point and also discuss case study where we have observed the changes in cost after implementing energy conservation measure.

Let us consider a building and its description

Sr. NO.




Square footage ( Floor)






Occupant density in occupy /1000 sqf



Air distribution system

central (CV)


Heating system

central heating with steam boiler


Cooling system

Chiller system (5 COP w per cooling tower)


Utility Bill –Gas

$0.490 unit charge


Utility bill – Electricity

$0.044 unit charge

Energy conservation measures

After studying the detailed description of building, further we will move towards energy conservation measure section where we will come to know following points.
  • What is energy conservation measure?
  • Type of energy conservation measure
  • Implementation of energy conservation measure
  • Advantage of energy conservation measure
  • Limitation of energy conservation measure
  • Live examples or case study of implementation of energy conservation measure
We can understand & implement energy conservation measures by considering one example as mentioned below. 

If we consider energy consumption in our building or in any residential areas, we may say that consumption of energy mainly depends on following factors.
  • Window & doors
  • HVAC
  • Lighting system
  • Refrigeration system
  • Structure
If we consider energy consumption in case of industrial field, we may see there that energy consumption mainly depends on the process and type of equipment. For example, if they use arc furnace instead of induction furnace for melting steel then they will consume more energy as compared to other those are using induction furnace for same process as arc furnaces consume more power as compared to induction furnace.

Energy conservation measures are defined as a project which is implemented in order to reduce the consumption of energy in commercial or residential buildings.

Here we have to consider energy conservation measure for our building that we have selected above. 

Energy conservation measures types

  • Water Conservation
  • Lighting system
  • Window & doors
  • Structures
  • Insulations
  • Electrical systems
  • Energy management control system
  • Motor & equipment
  • Renewable energy system
  • HVAC ( heating ventilation and air conditioning )
  • Air systems
  • Central cooling & heating units
  • System for heat recovery
Let’s consider lighting system

As we know that energy plays a vital role in country’s economical development hence it is very important to use energy efficient lighting system so that we can save energy and contribute in the development of our country. 

The meaning of energy efficiency is to secure the same output by using lesser quantity of energy. For example before some years peoples are using incandescent light bulb or lamps which is also known as traditional bulbs, but now day’s peoples are using fluorescent bulbs or lights.

If we consider between these two bulbs we may see that function of both are same but fluorescent bulbs or lights consume only 25 percentage of energy to provide the same output or we can say that by replacing incandescent light bulb or bulbs with fluorescent bulbs or lights saves energy by 75 percentage. 

One more thing which is very interesting that we will not only save energy but also we can reduce the pollution levels by using fluorescent bulbs or lights instead of incandescent light bulb or lamps. Energy consumption data shows that lighting system contributes 15% of total energy consumption for developing countries.

Let us consider one data provided by a developing country where we can see the total consumption of electricity and consumption of electricity for lighting in different areas.


Total consumption of electricity in percentage

Electricity consumed for lighting system in percentage of total consumption of electricity



4 to 5



50 to 90



4 to 5



1.5 to 2

Let us consider the energy consumption in lighting
Graph shows that consumption of electricity in Japan for lighting is approximate 7 times 
In order to reduce the consumption of electricity in lighting, all countries are using most energy efficient equipment with securing same output after consuming less energy, in following figure we may see that consumption of fluorescent bulbs or lams are quite more as compared to incandescent light or bulbs.

How we can save energy in lighting system

There are following ways to save energy in lighting system 

Use of compact fluorescent lamp or bulbs instead of incandescent light bulb

As we have discussed earlier compact fluorescent lamp or bulbs consumes only 25 percentage of energy consumed by incandescent light bulb and producing better output
Saving = 75 percentage.

Use of LED lamps or bulbs instead of incandescent light bulb 

LED lamps or bulbs use light emitting diodes to produce the light, at initial state the cost of LED lamps or bulbs will be higher as compared to incandescent light bulb and also higher as compared to fluorescent lamp or bulbs.

Use of natural lights: skylights

It is the best way to save energy; skylight will provide 20 times more than fluorescent lamp or bulbs and incandescent light. We have to just arrange our windows in good positions and we have to use light reflecting paints on our wall. 

Solar lights

As we know that solar light is a renewable source of energy and we can produce it at our end with the help of sunlight and solar cell. We can see this normally in garden to light the garden and pathways by converting sunlight in to electrical energy or lights. 

Other point need to consider 

Uses of smart glass on window can reduce the consumption of energy in lighting. 

By using programmable thermostat we may save approximate 100 $ per annum in energy  consumption bill. 

We should prefer lighting audit in order to know the current situation of consumption and to secure the guidelines by auditor to reduce the consumption.

Building science

In building science we have to find the factors those are affecting the performance of building. For example we determine that how heat transfer, air flow, relative humidity & moisture affect the performance of building. 

Building Science – Form of energy

In below mentioned figure we may understand that what type of energy are required to understand in building science.

Kinetic energy (transition energy)
Potential energy (stored Energy)

Logs burning

Water at dam

Light from flashlight


Hydro carbon fuels combustion


Building Science – Transfer of heat

Heat transfer in a building takes place via all 3 modes Conduction, convection & radiation
·         Heat transfer from sun to earth or home takes place via radiation
·         Heat transfer from outside to inside through wall takes place via conduction
·         Heat transfer inside takes place via convection for example transfer of heat between airs in a room.

Building Science – Moisture

Moistures are found in following way
  • Liquid moisture
  • Vapor of water
  • Condensate

Building Science – Relativity humidity

Moisture could be measure by relativity humidity and it depends on the temperature of air inside building.

Case study – Success in practice

Alumni Memorial hall-case study
In year 1999, certain changes were carried out to reduce the consumption of electricity in Alumni Memorial hall.
  • Four hundred & forty lamps are replaced
  • Fluorescent lamps are used instead of thirty three incandescent light bulb
We may see the result of these changes in following chart, where electricity consumption in lighting reduced by considerable amount.

GG Brown- Case study

In year 2000, certain changes were carried out to reduce the consumption of electricity.
Fluorescent lamps were used instead of three thousand incandescent light bulbs and a better result was obtained that can be seen in following chart.

Electricity consumption in lighting was reduced by considerable amount in year 2000 ends.
In following chart we may see the costing in year 2000 as compared to previous years.

Simple pay back –Calculation

Simple payback cold be calculated by using the following formula
Simple payback = Total cost of energy efficient product / annual saving
In this project as we have decided to work on only lightening , so we will calculate simple payback in years for lightening system after implementing energy efficient devices.

Previously we are using following electric devices in our house.

Sr. No



Working hours/day

Consumption of electricity


Electric bulb (100 W)



15 KW-h


Fridge 22 Cu-ft



5 KW-h

Now we have replaced all electric bulb by 20 W CFL and we have also replaced fridge that uses now 1.5 KW-h per day instead of 5 kw-h.

So total consumption of electricity after replacement, 4.5 KW-h per day for lightening and fridge.

Saving = 20-4.5= 15.5 KW-h per day
Saving in 1 year = 5657.5 KW-h
Cost of electricity= $0.044 unit charge
Saving in $ = 248.93
Total cost of energy efficient product Let = $1000
Simple Payback in year = 1000/248.93= 4
Hence simple payback in year = 4

Cash flow analysis

Let we have taken $5000 as borrow money for energy efficient product. Let it is 20 year mortgage at 6 percentage of interest; hence we may say that cost of borrowing money will be $430 per year.

After investing, cost in energy bill that we are saving = $ 248.93 or $249
So we may show the cash flow in given table
Let 7% energy cost inflation


Mortgage –cost


Cost of maintenance


Energy saving ($)

Net cash flow




















































Hence, we can say that investment that we have done will produce positive cash flow in year 10.

Building performance index

Building performance index can be calculated by ratio of total energy used to total built-up area
BEPI= total energy used /total built-up area


We may see the disadvantage or limitations of implementing above features
  • As we know that these type energy saving bulbs and lamps are using mercury and mercury is very dangerous. If these types are bulbs are lamps are broken then we have to use mask to avoid the effect of inhaling of mercury.
  • Initial cost is high as compared to other normal incandescent light bulbs
  • LED lamps are also very dangerous to our health as they consist with toxic substances.


One more point of saving electricity can be seen by using automatic controls .in this type of technologies sensors are used to ensure the quality use of electricity. Sensors sense the presence of people by their movement or by heat released from their body. 
Once sensor senses the presence of people in room, switch will be turned ON and similarly when sensor detects that there is no person in room then switch will be turned OFF.

Hence this type of automatic control will be able to save energy by considerable amount.
Now we may see the how much electricity can be saved by using this sensor technology which works on the principle of Doppler Effect principle.

Energy saving in percentage
Class rooms
20 to 75
Rest rooms
30 to 75
30 to 60
15 to 60

Dimming controls are also used to save electricity consumption .this technology reduces the intensity of light when there is no one in room. But there are limitations of using this technology as all energy efficient bulbs or lights do not operate on the circuit of these controls.


So, we may say that there is lot of options to improve the energy consumption and to save the cost as compared to other area of economy after studying energy conservation measure; we came to know following points

By using energy efficient items we will be able to save energy and simultaneously energy bill also.

We should use the equipment as per requirement, if we use such items those are producing so much energy that could not be converted in to useful energy then it shows that we are losing energy without securing any result.

After saving energy we will be able to protect our environment also.

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